The present invention is generally directed to material handling vehicles and, more particularly, to a vehicle having a rotatable platform upon which to secure a load and an adjustable safety bumper.
Automatic guided vehicles (AGVs) are used throughout the material handling industry to transport loads. The term AGV is commonly used to refer to robust vehicle designs having any of a number of available automated guidance systems. Automatic guided carts (AGCS) is a term commonly used to refer to a less robust vehicle used for similar but smaller-scale applications. Current AGC designs generally include a frame with swivel castors located at the four corners of the frame. Other features may include a drive wheel assembly and rigid castors for directional control of the cart. In one current design, two rigid castors are fixed to the frame and located approximately midway between the swivel castors on each side of the cart frame. The two pair of swivel castor axes and the rigid castor axis are generally parallel to each other. The steerable driving unit is attached to the cart frame, generally by way of a plate that is hinged and spring loaded from the cart frame to ensure that the steerable drive wheel maintains adequate traction with the support surface.
It is known in the art for an AGV to include a rotatable platform that is attached to the cart frame to which the load may be secured. The rotatable platform allows for the load to be rotated as desired and independently of the direction of travel of the AGV. This is particularly useful in a manufacturing assembly line where the load comprises a workpiece that is operated upon by a worker. It may be advantageous for the workpiece to rotate so that the worker is able to operate upon all sides of the workpiece while remaining in the approximately same position in relation to the AGV.
Various safety mechanisms are currently utilized to prevent an AGV from colliding with persons or other objects, or injuring a person or damage to an object if a collision occurs. Sonic or optical sensors may be utilized to detect an object within a predetermined distance in the AGV's path of travel and, if an object is sensed, the AGV halts movement. A mechanical bumper may also be used, in conjunction with or separate from the object detection sensors described above, to prevent injury resulting from a collision. The bumpers are commonly composed of a “soft” material, e.g., rubber, that will absorb the energy from a collision. Pressure sensors may be disposed on or within a bumper to detect a collision and halt the travel of the AGV.
Despite the presence of the individual components described above, their satisfactory combination has yet to be addressed in the art. A rotatable load that is larger than the AGV and asymmetrical, e.g., longer than it is wide, presents a number of operational difficulties with the known safety mechanisms described above.